title: Erosive osteoarthritis: a more severe form of radiographic hand osteoarthritis rather than a distinct entity?
abstract: OBJECTIVE
  To determine whether erosive osteoarthritis shares the same pattern of joint involvement and risk profile as increasing grades of non-erosive hand osteoarthritis.
  
  
  METHODS
  Participants were from two population-based cohorts, aged ≥50 years, reporting hand symptoms in the previous month. Interphalangeal joints were assessed for erosive osteoarthritis (Verbruggen-Veys erosive or remodelled phase) and radiographic osteoarthritis (sliding cut-offs of K&L≥2, K&L≥3 and K&L=4). At the joint level, similarities in the frequency and pattern of erosive and non-erosive osteoarthritis were assessed by Spearman's rank correlation coefficients and generalised estimating equations. At the person level, individuals with erosive osteoarthritis were compared to those with non-erosive osteoarthritis using logistic regression, adjusted for age and gender (aOR), for the following exposures: family history, previous injury, overuse and metabolic factors (BMI, dyslipidaemia, hypertension, diabetes).
  
  
  RESULTS
  In 1076 symptomatic participants the ranked frequency of involvement for erosive joints was comparable to joints with K&L≥3 and K&L=4 (r>0.95). Patterns of joint involvement in erosive osteoarthritis were strongest for symmetry (aOR=6.5; 95% CI 3.0 to 14.1), followed by row (2.0; 0.8 to 5.0) and ray (0.3; 0.0 to 2.5), which was similar to joints with K&L≥3 and K&L=4. Individuals with erosive osteoarthritis (n=80) had an increased risk of metabolic syndrome (2.7; 1.0 to 7.1), notably dyslipidaemia (4.7; 2.1 to 10.6) compared with non-erosive osteoarthritis classed K&L≥3 (n=193).
  
  
  CONCLUSIONS
  The similar frequency of radiographic joint involvement and patterning in erosive osteoarthritis and more severe non-erosive osteoarthritis is consistent with prevalent erosive osteoarthritis being a severe form of hand osteoarthritis rather than a distinct entity. Metabolic exposures, dyslipidaemia in particular, may be implicated in erosive osteoarthritis.
authors.affiliation: Arthritis Research UK Primary Care Centre, Primary Care Sciences, Keele University, Staffordshire, UK.
authors.forename: Michelle
authors.initials: M
authors.lastname: Marshall
authors.affiliation: Arthritis Research UK Primary Care Centre, Primary Care Sciences, Keele University, Staffordshire, UK.
authors.forename: Elaine
authors.initials: E
authors.lastname: Nicholls
authors.affiliation: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Wing-Yee
authors.initials: WY
authors.lastname: Kwok
authors.affiliation: Arthritis Research UK Primary Care Centre, Primary Care Sciences, Keele University, Staffordshire, UK.
authors.forename: George
authors.initials: G
authors.lastname: Peat
authors.affiliation: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Margreet
authors.initials: M
authors.lastname: Kloppenburg
authors.affiliation: Arthritis Research UK Primary Care Centre, Primary Care Sciences, Keele University, Staffordshire, UK.
authors.forename: Danielle
authors.initials: D
authors.lastname: van der Windt
authors.affiliation: Arthritis Research UK Primary Care Centre, Primary Care Sciences, Keele University, Staffordshire, UK.
authors.forename: Helen
authors.initials: H
authors.lastname: Myers
authors.affiliation: Arthritis Research UK Primary Care Centre, Primary Care Sciences, Keele University, Staffordshire, UK.
authors.forename: Krysia
authors.initials: K
authors.lastname: Dziedzic
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D050171:Dyslipidemias / Q000453:epidemiology; D005260:Female; D005384:Finger Joint / Q000000981:diagnostic imaging*; D050823:Hand Joints / Q000000981:diagnostic imaging*; D006801:Humans; D016015:Logistic Models; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology; D008875:Middle Aged; D010003:Osteoarthritis / Q000145:classification / Q000000981:diagnostic imaging* / Q000453:epidemiology; D011859:Radiography; D012720:Severity of Illness Index
keywords: Epidemiology; Hand Osteoarthritis; Osteoarthritis